Question 1

What raw score in a normal distribution would correspond to a z score of 1.56 with a mean equal to 75 and standard deviation of 2?

Accepted Answer

To find the raw score, we can use the formula:
z = (X - μ) / σ
where z = 1.56, μ = 75 and σ = 2. Rearranging the formula:
X = z * σ + μ
X = 1.56 * 2 + 75
X = 78.12
Therefore, the raw score corresponding to a z score of 1.56 with a mean of 75 and standard deviation of 2 is 78.12. Option (A) is the correct answer.

Question 2

If you want to compare scores for example your math score and score on your psychology exam you should_____.

Accepted Answer

The answer of If you want to compare scores for...

Question 3

Police officers must take an exam before they are hired in the department.Jack's has a T-score on the exam was 50 and John's T-score was 60.Who will most likely get hired?

Accepted Answer

The answer of Police officers must take an exam before...

Question 4

An instructor has given his final exam and scores that are normally distributed.Nancy scores a 90 and Ronald scores a 75.The class mean on the exam was 85 and the standard deviation was 36.What is Nancy's T score? (Hint use formula: mean=50 +10 (standard or Zscore)

Accepted Answer

The answer of An instructor has given his final exam...

Question 5

Assume you have a normal distribution with a mean of 5 and a standard deviation of 2.What proportion of scores fall between the raw scores of 7 and 9?

Accepted Answer

The answer of Assume you have a normal distribution with...

Question 6

What proportion of scores in a normal distribution lies between z scores of -1.55and +1.55?

Accepted Answer

The answer of What proportion of scores in a normal...

Question 7

The number of standard deviation units that a score falls above or below the mean is represented by the _____.

Accepted Answer

Standard deviation measures the distance between a score and the mean in standard deviation units, and this is represented by the standard score. The median frequency and percentile rank both represent the score's position in a distribution, while relative frequency shows the proportion of scores in a certain category.

Question 8

The scores below represent the results of an in-class quiz worth 10 points.
What is the cumulative frequency associated with a score of 6?

Accepted Answer

To find the cumulative frequency associated with a score of 6, we need to add up the frequencies of all scores less than or equal to 6. From the data given, we can see that there are 2 students who scored a 3, 3 students who scored a 4, and 2 students who scored a 5. Adding those up, we get a frequency of 2 + 3 + 2 = 7 for scores less than or equal to 6. Therefore, the answer is C.

Question 9

Julie took the same psychology exam as John and received a score of 65 what is her standard score?

Accepted Answer

The answer of Julie took the same psychology exam as...

Question 10

The scores below represent the results of an in-class quiz worth 10 points.
How many students had a score at or below 8?

Accepted Answer

To find out how many students had a score at or below 8, we need to add up the scores of all the students who took the quiz and then count the number of students who had a score at or below 8. Let's assume there were 100 students who took the quiz. If we add up all their scores, we get 1000 (100 students x 10 points each). To find out how many students had a score at or below 8, we need to find what percentage of 1000 is 8 or below. We can do this by dividing 8 by 1000 and then multiplying the result by 100. This gives us 0.008, which we can multiply by 100 to get 0.8%. Therefore, the percentage of students who had a score at or below 8 is approximately 0.8%. However, since none of the answer choices are exactly 0.8%, the closest one is 75%, which is the same as 0.75. Therefore, the best choice is A) 75%.

Question 11

Percentiles are based on what scale of measurement?

Accepted Answer

Percentiles are based on ordinal scale of measurement, where the data is ranked in a specific order but the differences between the values are not necessarily equal.

Question 12

An instructor has given his final exam and scores that are normally distributed.Nancy scores a 90 and Ronald scores a 75.The class mean on the exam was 85 and the standard deviation was 36.
What is Nancy's z score?

Accepted Answer

The z-score is calculated using the formula $z = \frac{(X - \mu)}{\sigma}$, where $X$ is the score, $\mu$ is the mean, and $\sigma$ is the standard deviation. For Nancy, $X = 90$, $\mu = 85$, and $\sigma = 36$, so $z = \frac{(90 - 85)}{36} = \frac{5}{36} = 0.14$.

Question 13

IQ test are based on a normal distribution.If someone's Standard score is 0 what is his IQ?

Accepted Answer

In a normal distribution for IQ scores, a standard score of 0 corresponds to the mean IQ, which is set at 100.

Question 14

The scores below represent the results of an in-class quiz worth 10 points.
How many students scored a 7 on the exam?

Accepted Answer

The answer of The scores below represent the results of...

Question 15

What proportion of scores are equal to a SD=1 in a normal distribution?

Accepted Answer

In a normal distribution, approximately 34.13% of scores fall within one standard deviation above or below the mean. Therefore, option C is correct. Option A (68.26%) represents the proportion of scores falling within two standard deviations, and option B (13.59%) represents the proportion of scores falling within one standard deviation on either side of the mean. Option D is incorrect as one of the other options is correct.

Question 16

The scores below represent the results of an in-class quiz worth 10 points.
How many students scored a 5 or below?

Accepted Answer

The answer of The scores below represent the results of...

Question 17

John scored an 85 on his psychology exam.The class mean was 75 and the standard deviation was 4.What is John's standard score?

Accepted Answer

Standard score or z-score is calculated by subtracting the mean from the raw score and then dividing the result by the standard deviation.

z-score = (raw score - mean) / standard deviation

In this case, 
z-score = (85 - 75) / 4 = 2.5

Since John scored above the mean, his z-score will be positive. Therefore, the answer is A) 2.5.

Question 18

The scores below represent the results of an in-class quiz worth 10 points.
What is the relative frequency associated with a score of 9?

Accepted Answer

The answer of The scores below represent the results of...

Question 19

An instructor has given his final exam and scores that are normally distributed.Nancy scores a 90 and Ronald scores a 75.The class mean on the exam was 85 and the standard deviation was 36.What is Ronald's z score?

Accepted Answer

The answer of An instructor has given his final exam...

Question 20

What proportion of scores in a normal distribution are above z = 1.96 and below z = -2.17?

Accepted Answer

The area under the normal distribution curve between z = -2.17 and z = 1.96 represents the majority of the data, leaving small proportions in the tails beyond these points. The area beyond z = 1.96 is approximately 2.5% of the total area under the curve, and the area beyond z = -2.17 is even smaller. Adding these two areas gives a proportion much smaller than the main body of the distribution, with the exact proportion depending on standard normal distribution tables or calculations. The closest option given is .0400, which approximates the combined area in the tails beyond z = 1.96 and z = -2.17.

Quiz 4: Percentiles percentile Ranks standard Scores and the Normal Distribution

What raw score in a normal distribution would correspond to a z score of 1.56 with a mean equal to 75 and standard deviation of 2?

If you want to compare scores for example your math score and score on your psychology exam you should_____.

Police officers must take an exam before they are hired in the department.Jack's has a T-score on the exam was 50 and John's T-score was 60.Who will most likely get hired?

An instructor has given his final exam and scores that are normally distributed.Nancy scores a 90 and Ronald scores a 75.The class mean on the exam was 85 and the standard deviation was 36.What is Nancy's T score? (Hint use formula: mean=50 +10 (standard or Zscore)

Assume you have a normal distribution with a mean of 5 and a standard deviation of 2.What proportion of scores fall between the raw scores of 7 and 9?

What proportion of scores in a normal distribution lies between z scores of -1.55and +1.55?

The number of standard deviation units that a score falls above or below the mean is represented by the _____.

The scores below represent the results of an in-class quiz worth 10 points. What is the cumulative frequency associated with a score of 6?

Julie took the same psychology exam as John and received a score of 65 what is her standard score?

The scores below represent the results of an in-class quiz worth 10 points. How many students had a score at or below 8?

Percentiles are based on what scale of measurement?

An instructor has given his final exam and scores that are normally distributed.Nancy scores a 90 and Ronald scores a 75.The class mean on the exam was 85 and the standard deviation was 36. What is Nancy's z score?

IQ test are based on a normal distribution.If someone's Standard score is 0 what is his IQ?

The scores below represent the results of an in-class quiz worth 10 points. How many students scored a 7 on the exam?

What proportion of scores are equal to a SD=1 in a normal distribution?

The scores below represent the results of an in-class quiz worth 10 points. How many students scored a 5 or below?

John scored an 85 on his psychology exam.The class mean was 75 and the standard deviation was 4.What is John's standard score?

The scores below represent the results of an in-class quiz worth 10 points. What is the relative frequency associated with a score of 9?

An instructor has given his final exam and scores that are normally distributed.Nancy scores a 90 and Ronald scores a 75.The class mean on the exam was 85 and the standard deviation was 36.What is Ronald's z score?

What proportion of scores in a normal distribution are above z = 1.96 and below z = -2.17?